instance method `fetch`

Ruby on Rails 5.2.8.1

Since v4.0.13

Available in: v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

fetch(key, *args)

Returns a parameter for the given key. If the key can’t be found, there are several options: With no other arguments, it will raise an ActionController::ParameterMissing error; if a second argument is given, then that is returned (converted to an instance of ActionController::Parameters if possible); if a block is given, then that will be run and its result returned.

params = ActionController::Parameters.new(person: { name: "Francesco" })
params.fetch(:person)               # => <ActionController::Parameters {"name"=>"Francesco"} permitted: false>
params.fetch(:none)                 # => ActionController::ParameterMissing: param is missing or the value is empty: none
params.fetch(:none, {})             # => <ActionController::Parameters {} permitted: false>
params.fetch(:none, "Francesco")    # => "Francesco"
params.fetch(:none) { "Francesco" } # => "Francesco"

Parameters

key req
args rest

Source

# File actionpack/lib/action_controller/metal/strong_parameters.rb, line 576
    def fetch(key, *args)
      convert_value_to_parameters(
        @parameters.fetch(key) {
          if block_given?
            yield
          else
            args.fetch(0) { raise ActionController::ParameterMissing.new(key) }
          end
        }
      )
    end

Defined in actionpack/lib/action_controller/metal/strong_parameters.rb line 576 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActionController::Parameters

Signature

Parameters